Summary
Highlights
The journey of CRISPR began in 1987 when Japanese scientists observed unusual palindromic DNA sequences in E. coli bacteria. They couldn't determine their purpose and simply reported their existence.
In 1990, Francisco Mojica found similar sequences in archaea. He named them CRISPR (clustered regularly interspaced short palindromic repeats) and hypothesized that the non-palindromic 'spacer' regions were viral DNA, possibly indicating an immune system.
In 2006, Philippe Horvath, working in a yogurt factory, demonstrated that CRISPR functions as an adaptive immune system in bacteria. He showed that resistant bacteria had viral DNA in their CRISPR arrays and that immunity depended on a precise DNA match with the target virus. He also identified Cas9, a protein enzyme responsible for cutting viral DNA.
A year later, John van der Oost created artificial CRISPR arrays, demonstrating programmable CRISPR-based immunity. In 2012, Emmanuelle Charpentier discovered tracer RNA, the last essential component, establishing the full mechanism of CRISPR.
By 2013, CRISPR became a major scientific focus. Virginijus Šikšnys moved the system to an in vitro environment, and Charpentier and Jennifer Doudna created single guide RNA (sgRNA) for optimization. Feng Zhang and George Church successfully adapted CRISPR-Cas9 for efficient and accurate genome editing in mammalian cells, opening possibilities for disease prevention and genetic enhancement.